Senate Homeland Security and Governmental Affairs Chairman Ron Johnson isn't ruling out further challenges to the Obama administration's treatment of members of Congress and their staff members under the Affordable Care Act.

The U.S. Court of Appeals for the 7th Circuit on Tuesday agreed with a lower court ruling that the Wisconsin Republican and his Senate counsel lacked standing because neither of them could show an injury from the Office of Personnel Management's determination that federal employees making use of the District of Columbia's health care exchange are eligible for employer contributions. "Respectfully, we do not see how Senator Johnson’s reputation could be sullied or his electability diminished by being offered, against his will, a benefit that he then decided to refuse. He could not be accused of participating in an illegal scheme if he declined to participate," the 7th Circuit opinion said.

But that's not stopping the first-term senator, who faces re-election next year.

"For the second time, my attempt to restore the constitutional balance between the executive and legislative co-equal branches of government has been stymied by the courts. With this decision today, another executive action by the administration will go unchallenged, all based on the legal technicality of standing," the Wisconsin Republican said.

"My legal team and I will carefully review the decision before determining our next step in this important constitutional dispute. I want to personally thank the tens of thousands of great Americans who have supported this effort," he continued. "We've lost a battle in court, but we will continue to move forward in our effort to return sanity, fairness and balance to government on behalf of the American people."